a. Field
This disclosure relates to a hemostasis valve. In particular, the disclosure relates to a hemostasis valve that enables insertion of catheters and other medical devices into an introducer sheath, and removal of the devices from the sheath, with relatively little force while maintaining a fluid tight seal.
b. Background
A wide variety of medical devices are inserted into the body to diagnose and treat various medical conditions. Catheters, for example, are used to perform a variety of tasks within human bodies and other bodies including the delivery of medicine and fluids, the removal of bodily fluids and the transport of surgical tools and instruments. In the diagnosis and treatment of atrial fibrillation, for example, catheters may be used to deliver electrodes to the heart for electrophysiological mapping of the surface of the heart and to deliver ablative energy to the surface among other tasks. Catheters are typically routed to a region of interest through the body's vascular system. In a conventional approach, an introducer is used to puncture the skin surface and a sheath having an inner diameter greater than the outer diameter of the catheter is threaded through the vasculature to a region of interest. The catheter is then moved longitudinally through the sheath to the region of interest either manually by a clinician or through the use of electromechanical drive systems.
Conventional sheaths have a hemostasis valve at a proximal end of the sheath. The hemostasis valve allows for the introduction of catheters, guide wires and other medical devices into and through the sheath while preventing blood and other fluids from exiting. The valve also allows for removal of the devices while preventing air from entering the vasculature. The valve provides a seal around the medical device. In a conventional hemostasis valve, the seal is formed by one or more gaskets having a shaped slit through which the device passes. The frictional force applied by the gasket(s) to the medical device requires a relatively high amount of force to overcome. As a result, controlled insertion of the medical device is difficult.